French onion soup with mac and cheese topping

Ingredients:

Soup

• 65 g unsalted butter
• 4 medium onions, thinly sliced ​​(about 14 cups)
• 2 bay leaves
• 2-3 fresh sprigs of thyme
• 1 cup dry white wine
• 4 cups lightly salted beef broth

Mac and cheese

• 100 g of pasta (1 cup)
• 2 tablespoons unsalted butter
• 2 tbsp. flour
• 3/4 cup milk
• 1 and 3/4 cups grated Gruyere
• 1 and 3/4 tbsp. grated sharp yellow cheddar
• 2 tablespoons panko breadcrumbs
• Special equipment: 4 soup pots with a capacity of 360 ml.

Preparation:

1. Soup:
   
   In a large Dutch oven or saucepan, melt the butter over medium heat. Add half the onion and sprinkle with 1/4 teaspoon of salt. Season with pepper to taste. Top with the remaining onion, sprinkle with 1/4 teaspoon of salt, and season with pepper to taste. Add the bay leaf and thyme. Cook, stirring occasionally, until all the liquid has evaporated and the onion is very soft and just beginning to darken, 45 minutes to 1 hour.
2. Add the white wine, bring to a simmer, and cook, stirring, until almost completely evaporated, about 6 minutes. Pour in the beef broth and 1 cup of water, bring to a vigorous boil, and simmer until the soup has reduced to 5 cups, 30-40 minutes. Season with salt and pepper to taste. Remove the bay leaf and thyme. Either simmer the soup or let it cool completely and refrigerate for reheating later. The soup can be made in advance and stored in the refrigerator for up to 2 days or frozen for up to 1 month..
3. Mac and cheese:
   
   Bring water to a boil in a medium saucepan, add pasta, and cook according to package directions. Drain, setting aside 0.5 cups of water.
4. In a medium saucepan over medium heat, melt the butter. Stir in the flour until smooth, about 2 minutes. Gradually whisk in the milk and pasta water. Stir until the liquid thickens, about 4 minutes. Add 1 cup of each cheese, 1/2 teaspoon of salt, and a pinch of freshly ground black pepper; stir until the cheese melts and the sauce is smooth. Remove from heat and stir in the cooked pasta until completely coated. Let cool slightly, stirring frequently.
5. Preheat the oven to broil. Place the ramekins on a rimmed baking sheet and ladle the hot soup into the ramekins, filling them about three-quarters full. Top each serving with a quarter of the mac and cheese (some of the mac and cheese will sink to the bottom, that's okay). Sprinkle evenly with the remaining cheese and breadcrumbsGrill until the cheese is melted and browned in spots, 2 to 3 minutes (the soup will bubble and some may leak out). Serve hot.